Extension of the PlatformTransactionManager
interface, indicating a native resource transaction manager, operating on a single
target resource. Such transaction managers differ from JTA transaction managers in
that they do not use XA transaction enlistment for an open number of resources but
rather focus on leveraging the native power and simplicity of a single target resource.

This interface is mainly used for abstract introspection of a transaction manager,
giving clients a hint on what kind of transaction manager they have been given
and on what concrete resource the transaction manager is operating on.